NSW Police have been asked to investigate more than 100 acts of animal cruelty at an Inghams turkey abattoir south west of Sydney, which animals activists have described as "torture".
ABC's Lateline program has been provided with an hour's worth of material by the group Animal Liberation.
The footage was secretly filmed over two weeks in an area of the Tahmoor abattoir where workers take the birds from cages and place them into shackles to be stunned and slaughtered.
"I think this is definitely some of the worst that we've [ever] seen," Animal Liberation's Emma Hurst said.
Workers can been seen kicking the birds, sometimes up to nine times.
Other birds are punched, bashed against walls or the cages and stomped on until they are still.
Sometimes co-workers kick or hit the same bird as it moves along the production line.
It appears to be common behaviour. Sometimes the workers appear to celebrate while those who see what is happening fail to intervene.
One worker even appears to try and separate a bird's head from its body by stretching and slotting it in the edge of a cage while it is attached to the moving production line.
"Every single day we found incidences of concern where workers are going out of their way to intentionally abuse these animals and cause harm on these animals. It’s just absolutely horrendous," Ms Hurst said.
Animal Liberation is not only concerned about the intentional harm, it has serious concerns about the general handling of the birds.
"Because these birds are so large it's not appropriate for them to be shackled," Mr Hurst said.
"[These] 8-17 kilogram animals [are the] same weight as a three-year-old child and it's being hung upside down by its ankles - we're actually seeing its feet rip off."
The footage shows numerous legs around the processing plant which have been tossed casually away by workers.
"If this sort of behaviour was witnessed in [the] general public there would be a huge outcry," said vet Dr Mark Simpson, who has worked with a number of animal welfare organisations.
"The people involved would be physically restrained, police would be involved and the full force of the law would be brought immediately to prevent further pain and suffering to animals."
Lateline has shown the footage to Inghams chief executive Kevin McBain who declined to be interviewed.
However, Mr McBain provided a statement saying: "We want to reassure Australians that Inghams does not tolerate the mistreatment of our livestock.
"We condemn the animal abuse we have seen in the footage and will – as a matter of urgency – work to review, retrain and reinforce our animal welfare standards throughout our organisation.
"We are investigating and working with all relevant parties to address and resolve these intolerable incidents."
Animal welfare groups are now demanding constant CCTV monitoring in all abattoirs.
"I'll be making a strong call in my report for mandatory video monitoring of these critical stages in the processing of slaughtering animals," Dr Simpson said.
"Animals give their life for the benefit of humans and we have a responsibility to make sure where this happens, it happens as humanely as possible."
The footage has been handed to NSW police for investigation.